DE4033155C2 - - Google Patents

Description

Field of application of the invention

The invention relates to a hydrophobizing or insulating agent Silicone base for organic and inorganic substances, such as B. Wood, concrete, gas concrete, mortar and brickwork, for prevention or delay the penetration of water and thus prematurely Destruction.

Characteristic of the known prior art

It is known to use organosilicon compounds in the form of monomeric, oligomeric or polymeric compounds as water repellents for use inorganic substances. For the hydrophobization of building materials alkali methyl silicates, alkoxysilanes or Silicone resin solutions or emulsions. So far as aqueous solutions or emulsions are present, their depth of penetration is small and so their effect is not very pronounced. Silicone resin solutions are more suitable. Due to its cross-linked polymer structure, too whose penetration depth and migration capacity in the capillary system z. B. restricted by building materials.

The proposal to add water by adding RTV silicone rubber further lowering leads to a considerable Increase in costs. The use of less cross-linked oligoalkoxysiloxanes requires condensation catalysts, such as. B. organotin Connections (DE 33 12 911). Another disadvantage is their low alkali stability.

It has been proposed to improve them, the usual ones so far Methyl residues on silicon due to higher, possibly branched alkyl residues, such as B. iso-propyl or octyl, to replace and To use organosilanes as monomeric alkoxysilane solutions (GB 13 02 529, color and varnish 95, (1989), 478). The production however, such connections are complex and lead to cost increases and does not justify the success achieved. Especially for porous Gas silicate concrete has been proposed (DE 21 22 979), a butoxymethylpolysiloxane  Mixtures of dimethyltetrabutoxydisilane, disiloxane and disilmethylene add as monomeric compounds. Apart from this, that the production of these monomeric substances is extremely complex is, they are e.g. B. unsuitable on dense cement concrete.

As injectable fluids that act as capillaries and before especially against rising masonry moisture in old masonry are used with missing or defective horizontal locks, it is known to use synthetic resins which harden under the influence of moisture based on diisocyanate (DD 1 41 332, DD 1 47 561), the introduction into the masonry in any suitable way, can be done in particular through boreholes. Furthermore, bitumen solutions or special plastic mixtures recommended. The Migration of such substances in dampened building materials is however very limited. It is also known to use water glass solutions and solutions of alkali methyl siliconates individually or as a mixture, if necessary with the addition of solubilizers, such as. B. ethanol or Use isopropanol. They lead to the sealing of the capillaries due to gel formation, but have the disadvantage of the formation of secondary capillaries, which cancel the initially sealing effect. In addition, salts are introduced into the masonry, which is known have an adverse effect on the masonry. Since water is used as a solvent, the penetration and migration capacity of these substances limited. Short hole spacing and thus higher effort and greater consumption Insulants are the result. DD 2 13 010 describes the introduction monomeric substances in the masonry. A mixture is proposed from fatty acid (stearic acid) esters, alkyltrialkoxysilane, monomeric or oligomeric silicic acid esters and organic solvents. The disadvantage is that due to early hydrolysis form non-hydrophobic gels in moist masonry, which are graft-like impede the further penetration of water repellents. In addition, there is long-lasting odor nuisance due to contamination e.g. B. by oxidation of stearic acid. The production the alkylalkoxysilane used is complex and costly.  

It is also known to use organosilicon compounds which Hydrophobization of inorganic substances can be used, too for organic substances such as B. wood to apply. Your impact however, is much less. For example, methyl siliconates almost show no water repellent effect, moreover they are there in water dissolved, with fungicidal wood preservatives dissolved in organic solvents immiscible. Silicone resin solutions act as a result their highly networked structure like paints by using the Seal wood pores. The effect achieved with this is however through Crack formation and consequent destruction of the covering layer as a result the swelling and shrinking capacity of the wood in more or canceled less short time. Soak and saturate the wood with silicone oils changes the appearance and prevents subsequent Surface treatment with other substances such as paints, stains and the like. Ä. It has also been proposed to wood with alkylalkoxy compounds to be impregnated (JP 6 30 45 001), with larger-volume alkyl groups Leftovers such as B. iso-propyl or octyl radicals can be selected (Farbe und Lack, 95, (1989), p. 480). Such impregnating agents show an improved waterproofing effect compared to methylsilanes. However, the effect bears no relation to the technical one Effort and therefore the cost of producing such Connections are required.

From what is shown it appears that no hydrophobizing agent is known which is a highly effective and permanent protection against the ingress of moisture into both organic and also in inorganic substances, the hydrophobization in Form of injection is included.

Aim of the invention

The aim of the invention is to develop a water repellent silicone-based for organic and inorganic substances, such as. B. Wood, concretes, gas concrete, mortar and brickwork, both is applicable by external order as well as by injecting and a high one with low costs and low technical effort Has a degree of preservation or insulation.  

State the nature of the invention

The object of the invention was to provide a water repellent or Develop silicone-based insulating material that using from disilane-containing distillation residues from methylchlorosilane synthesis manufactured products

• - A highly effective when used on inorganic substances and represents a permanent impregnation effect,
• - when injecting the prevention of rising masonry moisture serves as well
• - When applied to organic substances, e.g. B. wood, without pores seal, provides adequate protection against moisture absorption, with conventional fungicides dissolved in organic solvents Wood preservatives are miscible and well tolerated and an afterthought Surface treatment not hindered.

According to the invention the object is achieved in that the water repellent or contains insulation

• (A) (a) 5 to 40% by mass, preferably 10 to 20% by mass, methylalkoxypoly (disilyl) siloxane with preferably 1 to 5% by mass alkoxy groups, prepared by single-stage alkoxylation and hydrolysis of distillation residues of methylchlorosilane synthesis and
  (b) 95 to 60% by mass of organic solvent or solvent mixture or
• (B) (a) 5 to 40% by mass, preferably 10 to 20% by mass, methylalkoxyoligo (disilyl) siloxane with preferably 6 to 20% by mass alkoxy groups and a molecular weight of 400 to 900, prepared by alkoxylation of distillation residues of methylchlorosilane synthesis containing disilane and
  (b) 95 to 60% by mass of organic solvent or solvent mixture or
• (C) Mixtures of (A) and (B) in a mass ratio of 2: 100 to 100: 2.

The alkoxy groups in (a) are preferably ethoxy or methoxy groups. Suitable solvents are, for example, hydrocarbons, e.g. B. white spirit, chlorinated hydrocarbons, alcohols, e.g. B. isopropanol, ethers, esters, ketones or mixtures thereof.

The hydrophobizing or insulating agents according to the invention are in the usual way on the inorganic to be hydrophobized Applied surface. The hydrophobizing effect is compared conventional methyl silicone resin solutions greatly improved. As a result of the high penetration depth, the hydrophobic effect increases on cement, lime cement and concrete around the two- up to three times. It is just as surprising that it is twice as much high resistance to freeze and thawing agents in case of hard frost exposure. Very dense and heavily used concrete streets or flight operating areas are highly hydrophobicized, whereby the usability of the areas concerned is significant extended.

The introduction of the insulating agent according to the invention Injection into the masonry is done in a known manner Boreholes. The insulating agent according to the invention spreads Because of its excellent ability to migrate even in the wet and salt-laden masonry and produced without additional Applying pressure an effective and permanent capillary water barrier against rising damp in old masonry.

The hydrophobization of organic substances takes place in the usual way Way by dipping, brushing or spraying. Three times Diving with interim drying guaranteed adequate impregnation. The water repellent according to the invention is with common, dissolved in organic solvents Wood preservatives, such as B. pentachlorophenol, permethrin, Lindane, thiram, tributyltin oxide, brown and coal tar, Dichlorofluoride, bis (N-cyclohexyldiazeniumdioxy) copper, amines miscible and compatible. The water repellency is compared conventional agents greatly improved without pore sealing will. A subsequent surface treatment is possible.  

Embodiments A. Hydrophobization of inorganic substances Example 1

Test specimen of mortar group 2 (corresponding to a mixing ratio from 1: 3: 8 cement to lime to standard sand) in dimensions 100mm x 70mm x 20mm were made two weeks after manufacture dried at room temperature and then by dipping during 10 sec. In the water repellent solution according to the invention. (A), the 7 mass% methylalkoxypoly (disilyl) siloxane as active ingredient in contained petrol solution, impregnated. After treatment the test specimens were dried again at room temperature for two weeks, then to test the water repellency effect Water storage (covering 2 cm) exposed and the percentage Water intake determined after 2, 6, 24 and 48 hours. A conventional water repellent based on methyl silicone resin was used for comparison with a resin content of 7% by mass.

The results are shown in Table 1.

Table 1

Example 2

Test specimen of mortar group 3 (corresponding to a mixing ratio 1: 3 cement to standard sand, w / z: 0.5) in dimensions 100 mm × 70 mm × 20 mm were 6 weeks after preparation at room temperature stored and then in the drying cabinet for 15 hours leave. After cooling to room temperature, the  Hydrophobization by immersion for one minute in the invention Water repellent solution acc. (B), the 10 mass% methylalkoxyoligo (disilyl) siloxane as an active ingredient in petrol solution contained. After a drying time of two weeks at room temperature the alkali stability of the hydrophobizing agent was tested by immersing the test specimens in a 10% KOH solution (Covering 2 cm) and determining the increase in mass over a period of time of 14 days. A conventional water repellent was used for comparison based on methyl silicone resin with a resin content of 10% by mass.

The results are shown in Table 2.

Table 2

Example 3

Model concrete was used to determine the frost-thaw resistance used the following characteristics: cement PZ 45, WZ 0.51, aggregate screening line B, concrete consistency V3, compaction 30%, after normal storage up to 28 days on the 29th and 30th day.

For this purpose, cube-shaped test specimens with an edge length of 100 mm were immersed in both the inventive and conventional hydrophobizing agents. Frosting began after storage for 78 days, with storage in water for the past four days. Compressive strength Rd 28 = 39 N · mm ^-2 .

The frost-thaw resistance was determined according to Surface immersion method. Immersion medium: 3% urea solution; every 10 changes: check weighing and visual assessment.

The results are shown in Table 3.  

Table 3

All water repellents were used in white spirit.

Example 4

To determine the water absorption, hydrophobization was carried out according to Example 3 Test specimens used after 58 days. The immersion depth was 10 mm, the immersion area 140 cm².

The results are shown in Table 4.

Table 4

Example 5

In several demolition bricks from the basic masonry of old buildings with an average moisture content of 10% by mass and contained Harmful salts, especially sulfate, chloride and traces Nitrate, insulating agent according to the invention was drilled, consisting of 9% by mass methylalkoxypoly (disilyl) siloxane, 6% by mass Methylalkoxyoligo (disilyl) siloxane, 5 mass% isopropanol and a mixture of 40% by mass of n-heptane and 60% by mass of n-octane, brought in. After a fixation period of 14 days, the Bricks cut into slices of approximately the same thickness 2.5 cm divided and the capillary water absorption of each disc compared to untreated samples of the same brick. Table 5 shows the capillary water absorption of the brick discs after 14 days of constant water storage depending on the distance for injecting.

Table 5

It can be seen that the capillary system of the invention treated brick, still half the distance of the injection boreholes from each other, absorbs far less water than the untreated brick, which proves an effective masonry waterproofing.

Example 6

An insulating agent according to the invention, consisting of 12% by mass Methylalkoxypoly (disilyl) siloxane, 85% by mass n-hexane and 3% by mass Isoamyl alcohol was used in a draining operation without additional Isolation measure without pressure through holes in the moisture-loaded Sandstone masonry introduced. Performed after 6 months Moisture measurements showed that even at a depth of 30 cm Masonry cross-section a 3.5 vol% lower moisture value  than could be measured before the injection. The wall blocks above the injecting level were clearly dry and soluble harmful salts due to the water loss on the surface efflorescence, what an action of the capillary water barrier in proves entire wall cross-section.

B. Hydrophobization of organic substances Example 1

5 pieces of sapwood from the common pine (Pinus silvestris L.) of 100 mm in length parallel to the fiber, 25 mm in width across the annual rings and 5 mm thick were at 20 ° C and 65% Air humidity conditioned, 3 times for 10 seconds each in the water repellent solution dipped and air-dried in the meantime. After setting to keep the weight constant, the wood was hung in water. Table 6 shows the average water intake in % By mass, based on the dry weight a and based on the Blank value b reproduced in the times indicated and with literature values (Farbe und Lack 95, (1989), 480).

Table 6

Table 6 (continued)

Table 7 shows the residual moisture as the average difference the masses of the test specimens after 24 h water storage and after specified drying time in g and in mass% per m².

Table 7

Example 2

The compatibility of the hydrophobicizing solution according to the invention with wood preservatives, three of each were detected woods described in Example 1 as hydrophobized there. The Water repellent solution consisted of pure "Kombinal" (merchandise) and from mixtures of this product with the invention Water repellents A. The measured after subsequent water storage Water intakes are summarized in Table 8 and compared to untreated test specimens.  

Table 8

Claims (9)

1. Hydrophobizing or insulating agent based on silicone for organic and inorganic substances, such as. B. wood, concrete, gas concrete, mortar and brick masonry, characterized in that it contains

• (A) (a) 5 to 40% by mass of methylalkoxypoly (disilyl) siloxane, produced by single-stage alkoxylation and hydrolysis of disilane-containing distillation residues from the synthesis of methylchlorosilane and
  (b) 95 to 60% by mass of organic solvent or solvent mixture or
• (B) (a) 5 to 40% by mass of methylalkoxyoligo (disilyl) siloxane, produced by alkoxylation of disilane-containing distillation residues from the synthesis of methylchlorosilane and
  (b) 95 to 60% by mass of organic solvent or solvent mixture or
• (C) Mixtures of (A) and (B) in a mass ratio of 2: 100 to 100: 2.

2. Hydrophobing or insulating agent according to claim 1, characterized characterized in that (a) in (A) or (B) 10 to 20% by mass is included. 3. Hydrophobing or insulating agent according to claim 1 and 2, characterized characterized in that the methylalkoxypoly (disilyl) siloxane 1 to Contains 5 mass% alkoxy groups. 4. Hydrophobing or insulating agent according to claim 1 and 2, characterized characterized in that the methylalkoxyoligo (disilyl) siloxane Contains 6 to 50 mass% alkoxy groups. 5. Hydrophobing or insulating agent according to claim 1 to 4, characterized characterized in that the alkoxy groups are methoxy or ethoxy groups are. 6. hydrophobizing or insulating agent according to claim 1 and 2, characterized characterized in that the methylalkoxyoligo (disilyl) siloxane a Has molecular weight from 400 to 900.   7. hydrophobizing or insulating agent according to claim 1, characterized characterized in that hydrocarbons, chlorinated hydrocarbons, Alcohols, ethers, esters and / or ketones are included. 8. Hydrophobing or insulating agent according to claim 7, characterized characterized in that they contain white spirit as the hydrocarbon is. 9. hydrophobizing or insulating agent according to claim 7, characterized characterized in that isopropanol is contained as alcohol.